Application of thymol and iprodione to control garlic white rot (Sclerotium cepivorum) and its effect on soil microbial communities

MINAMBRES G; CONLES Y; LUCINI EI; VERDENELLI R; MERILES JM; ZYGADLO JA

World J Microbiol Biotechnol

Springer-verlag

Lugar: Berlin; Año: 2010 vol. 26 p. 161 - 170

1573-0972

Abstract The effect of different dosages of thymol alone, iprodione alone and combinations of thymol and iprodione on white rot disease of garlic and its impact on soil microbial community structure were investigated under greenhouse conditions. Thymol alone or in combination with the fungicide iprodione did not appear to reduce either white rot incidence or soil sclerotia density as compared to an infected control. However, iprodione alone or in combination with thymol reduced soil fungal biomass. In addition, iprodione alone decreased soil microbial activity as estimated by fluorescein diacetate (FDA). Soil bacterial community structure as estimated by phospholipid fattyacid (PLFA) profiles was also was affected by both thymol and iprodione applications. The correlation biplot of the individual PLFAs and biocide treatment indicated that the treatments with thymol alone increased cyclopropyl fatty acid (cy17:0 and cy19:0), while the treatments withiprodione alone increased some saturated and branched fatty acids (principally i16:0, a15:0 and 18:0). In addition, taking into account PLFA biomarkers, thymol applications reduced Gram-negative bacteria in soil. To our knowledge,this research is the first report about the effect of a monoterpene (thymol) on soil microflora.